Electrical flashing device

ABSTRACT

The device comprises a circuit interrupter which is plugged into an electrical outlet. When an electrical lamp is plugged into the device, the lamp will flash on and off as the device intermittently interrupts the circuit. The flashing device comprises a rectangular housing having a base and a cover. The housing has a plurality of wall portions dividing the housing area into a plurality of segments. The various wall convolutions serve to frictionally retain the electrical parts without screws or other fastening means. A pair of identical blades are mounted for insertion in an electrical outlet. Internally, there are two identical contact elements. One contact is locked to one end of one of the blades. The other contact is spaced from the other blade. A bimetallic strip extends from the spaced contact toward the adjacent blade and is covered with a coil of fine wire. One end of the wire is attached to the contact and the other end to the blade. The blades are plugged into an electrical outlet. Now, when a lamp is plugged into the device, its blades touch the contacts to complete a circuit. Current will initially flow along the fine wire. The wire does not allow the passage of sufficient current to light the lamp. However, the current will heat up the coil of wire which will heat the bimetallic strip. This causes the strip to bend against the contact to allow the current to bypass the wire and light the lamp. The coil and strip cool sufficiently so that the strip bends away from the contact and the light goes out. The wire again heats up and the entire sequence is repeated, causing the lamp to flash on and off.

United States Patent 1191 Schwartz 1111 3,798,582 1451 Mar. 19, 1974 ELECTRICAL FLASHING DEVICE [75] Inventor: Frederic W. Schwartz, Providence,

[73] Assignee: Cable Electric Products, Inc., 9 Providence, RI.

221 Filed: Mar. 20, 1972 21 Appl. No.: 236,139

Primary ExaminerBe'rnard A. Gilheany Assistant Examiner-F. E. Bell Attorney, Agent, or Firm-Max Schwartz 57 ABSTRACT The device comprises a circuit interrupter which is plugged into an electrical outlet. When an electrical lamp is plugged into the device, the lamp will flash on and off as the device intermittently interrupts the circuit. The flashing device comprises a rectangular housing having a base and a cover. The housing has a plurality of wall portions dividing the housing area into a plurality of segments. The various wall convolutions serve to frictionally retain the electrical parts without screws or other fastening means. A pair of identical blades are mounted for insertion in an electrical outlet. Internally, there are two identical contact elements. One contact is locked to one end of one of the blades. The other contact is spaced from the other blade. A bimetallic strip extends from the spaced contact toward the adjacent blade and is covered with a coil of fine wire. One end of the wire is attached to the contact and the other end to the blade. The blades are plugged into an electrical outlet. Now, when a lamp is plugged into the device, its blades touch the contacts to complete a circuit. Current will initially flow along the fine wire. The wire does not allow the passage of sufficient current to light the lamp. How ever, the current will heat up the coil of wire which will heat the bimetallic strip. This causes the strip to bend against the contact to allow the current to bypass the wire and light the lamp. The coil and strip cool sufficiently so that the strip bends away from the contact and the light goes out. The wire again heats up and the entire sequence is repeated, causing the lamp to flash on and off.

2 Claims, 5 Drawing Figures ELECTRICAL FLASHING DEVICE BACKGROUND OF THE INVENTION Circuit interrupters are well known in the art. For example, the conventional house bell is provided with a clapper which is swung repeatedly back and forth by interrupting the circuit to an electromagnet. Circuit interrupters have been used for various purposes to supply intermittent current. The use of such a device for causing a light to flash is also known to the art. In some constructions a rotating disc is provided with serrated edges or gaps which make and break contacts.

However, all" these devices require a certain amount of manufacturing operations of the various parts and a plurality of assembly operations. The result is a somewhat bulky device which may be a little costly for the simple operation required.

SUMMARY OF THE INVENTION The present invention provides a flashing device which is reduced to a minimum in size and requires a minimum of assembly operations. The plastic dielectric housing is rectangular for compactness and easy assembly handling. The base and cover are mirrors of each others internal construction. A single form of a contact blade and a contact is used for both sides, reducing die costs and manufacturing operations. The blades and contacts are held in the housing by friction, eliminating intricate assembly operations.

Oneset of a blade and contact are locked to each other. The other set is separated. A bimetallic strip is mounted on the loose contact and extends toward the associated blade. A coil of fine wire surrounds the strip with one end of the wire attached to the contact and the other end to the blade. When current is applied, the line wire will not pass sufficient current to light ,the lamp.'However, the coil will heat up and heat the strip. The strip will bend until it touches the blade. This bypasses the coil, closes the circuit, and lights the lamp. The coil and strip now cool and the strip straightens. This breaks the circuit and the lamp goes out. The sequence is now repeated again causing the light to go on and then off again to provide a flashing light.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a device of the present invention in position in an electrical outlet;

FIG. 2 is an enlarged plan view of the device with the cover removed and the contacts in off position;

FIG. 3 is a fragmentary plan view of a portion of the base showing the contacts in on position;

FIG. 4 is an enlarged fragmentary section showing the mounting of the cover on the base; and

FIG. 5 is a perspective view of the blade and contact assembly.

DESCRIPTION OF THE INVENTION Referring more in detail to the drawings, the flasher device of the present invention comprises a rectangular, molded plastic, dielectric housing having a base and a cover 11. The base 10 and cover 11 are mirrors of eachrother, the base construction appearing identically, except in a mirror reversal, in the cover. The base 10 and cover 11 are provided with aligned central openings 12 through which a bolt 13 extends to lock the the parts together. To keep them in proper alignment, the base 10 is provided with an opening 14 adjacent one side edge, see-FIGS. 2 and 4, and the cover 1 1 is provided with apin l5 adated to enter the opening 14 in assembly. This keeps the base and cover from twisting.

To insert the device into a wall receptacle, thehousing is provided with a pair of spaced, parallel, identical, contact blades 16 and 17. Each blade is constructed as shown in FIG. 5. A springtype blade is provided with a straight section 18 having a short end 19 turned at right angles. The bowed spring portion 20 is connected to the straight section 18 at the bend 21 at the thrust end. The portion 20 is bent at right angles at 22 to extend over the bent end 19. The blade is then again bent parallel to the portion 18 for a short distance at 23. The portion 23 is provided at its end with a pair of lugs 24 at opposite side edges.

On the inside, the housing is provided with a pair of identical contacts, one of which is locked to the end of the blade 16 as shown in FIGS. 2 and 5. Each contact is bent in four places to provide a zig-zag effect. At one end there is a short portion 25 having cut out portions 26 at the side edges into which the lugs 24 are clamped to lock the contact to the blade. The contact is now bent at 27 at right angles for a short distance 28 and then bent at 29 at right angles in the opposite direction to form an elongated section 30. The section 30 has a cut out tongue member 31 which is bent out of the plane of the section 30 to form a resilient contact area. A bend 32 forms another short wall 33. Another bend 34 in the opposite direction forms the end portion 35. The portion 35 has a central opening 36 and a forwardly extending integral finger 37.

Now viewing FIG. 2, the base 10 (and cover 11) is provided with an integral transverse wall portion 38 dividing the housing into two areas. The blade 16 with its attached contact is mounted in the left area. The housing is provided with a slot 39 through which the blade 16 extends. The bent portions 19 and 22 are clamped against the inside wall by an auxiliary wall 40 which also supports the contact portion 30. The finger 37 at the end of the contact abuts the opposite wall. A slot 41 extends through this opposite wall for receiving one of the blades of an inserted plug. The spring tongue 31 extends into the slot area to contact the inserted blade.

On the right side, the blade 17 and its associated contact are separated by the housing wall 42. The blade 17 is mounted similarly to the blade 16, extending through a second slot 39. The end portion 23 is provided with a contact point 43. The contact is mounted on the opposite side of the wall 42 with its spring tongue 31 in the area of the slot 44 similar to the slot 41. The slots 41 and 44 receive the plug of the lamp or other appliance. The contact on the right is provided with a bimetallic strip 45 mounted at one end to the section 35 by a rivet 46. The strip 45 is surrounded by a coil of fine wire 47, approximately 250 turns of a 2,600 ohm wire. One end of the wire is attached to the contact, the other end 48 extends to the blade end 23. Finally, the free end of the strip 45 is provided with a contact point 49 normally in spaced relation to the contact point 43 on the blade 17.

In operation, the device is plugged into a receptacle, FIG. 1, with the blades 16 and 17 contacting the source of current in the conventional manner. Now, when a lamp (or other electrical appliance) is plugged into the slots 41 and 44 (dot and dash lines in FIG. 1), the

blades of the plug will contact the tongues 31. A circuit is now closed from the receptacle through the blade 16 and its contact, to the inserted plug and lamp, back to the other contact, through the bimetallic strip 45, coil 47, wire 48, to the blade 17. However, the resistance of the coil 47 is so great that the lamp will not receive sufficient current to light it. But the coil 47 will quickly heat up and heat the strip 45. This will cause it to bend until the contact points 43 and 49 touch. The circuit now flows through to contact and strip, bypassing the fine wire 47. The lamp goes on and the coil 47 and strip 45 cool off. In cooling, the strip 45 bends back into straight position separating the points 43 and 49. This puts out the light and forces the current back through the coil 47. Again the coil and strip heat up to close the contact points 43 and 49 and put the light on again. The entire process is repeated over and over to cause the light to flash on and off.

The operation is therefore accomplished without moving parts other than the bending of the bimetallic strip 45. The rectangular housing is small and compact, but easy assembly is accomplished by eliminating anchoring screws or clamps. Note that the blades and contacts are held in the housing by the frictional contact with the several wall portions. Parts are readily stamped, both blades and both contacts being identical so that two dies will make four parts. This makes for an efficient yet economical construction.

Other advantages of the present invention will be readily apparent to a person skilled in the art.

I claim:

1. An electrical flashing device comprising a housing having a base and a cover, a pair of blades extending from said housing adapted to be inserted into an electrical outlet, a pair of contacts mounted in said housing, one of said contacts being locked to one of said blades, the other of said contacts being separated from the other of said blades, a pair of slots in said housing opposite said blades, said contacts having portions extending each into one of said slots to electrically contact the blades of a plug inserted into said slots, a bimetallic strip mounted on said separated contact extending toward said other blade, a fine wire coiled around said strip and extending to said other blade, and contact means on said other blade and said strip for making electrical contact when said strip is bent out of alignment by the heat of said coil of wire, said blades each having a spring type thrust end with two lengths in folded relation, one length being straight with a short right angled bend at its free end, the other length being bowed with a bend extending over the other bend for retaining the blade in said housing, the bowed length extending into the housing and having an end portion with integral lugs at each side edge for attachment to a contact, each of said contacts comprising a strip bent in a zig-zag shape, one end having cut out portions for receiving said blade lugs, the other end having an opening for mounting said strip, and an intermediate portion having a cut out spring tongue extending into said slots.

2. A device as in claim 1, wherein said blades and contacts are frictionally retained in said housing. 

1. An electrical flashing device comprising a housing having a base and a cover, a pair of blades extending from said housing adapted to be inserted into an electrical outlet, a pair of contacts mounted in said housing, one of said contacts being locked to one of said blades, the other of said contacts being separated from the other of said blades, a pair of slots in said housing opposite said blades, said contacts having portions extending each into one of said slots to electrically contact the blades of a plug inserted into said slots, a bimetallic strip mounted on said separated contact extending toward said other blade, a fine wire coiled around said strip and extending to said other blade, and contact means on said other blade and said strip for making electrical contact when said strip is bent out of alignment by the heat of said coil of wire, said blades each having a spring type thrust end with two lengths in folded relation, one length being straight with a short right angled bend at its free end, the other length being bowed with a bend extending over the other bend for retaining the blade in said housing, the bowed length extending into the housing and having an end portion with integral lugs at each side edge for attachment to a contact, each of said contacts comprising a strip bent in a zig-zag shape, one end having cut out portions fOr receiving said blade lugs, the other end having an opening for mounting said strip, and an intermediate portion having a cut out spring tongue extending into said slots.
 2. A device as in claim 1, wherein said blades and contacts are frictionally retained in said housing. 